J3/06-103
To: J3
From: Michael Ingrassia
Subject: Fortran Standard as Literature
Date: 2005 December 7
I. Introduction
The FORTRAN standard is written for and read by FORTRAN
implementors. But it is also occasionally read "as literature"
by technically proficient readers outside the relatively
small community of Fortran implementors and Fortran standards
mavens. [By this I refer to readers with no contingent claims to stake on the
standard who merely wish to comprehend it.]
First-time readers may draw incorrect technical conclusions
if they are not able to discern aspects of the standard
which are fully derivable from the standard text and part of the
Fortran community consensus, but not written explicitly.
Where the standard is not defective, it cannot and of course should not be
changed by the Interpretation process.
But the occasion of printing a
new standard is an occasion for adding clarifying language about
historically misunderstood aspects, if it can be done without in any
way disturbing the existing consensus. Adding such language
is a service to the wider technical community.
II. Edit
Add NOTE 7.16.5 at [130:4+] after
"the processor may evaluate any mathematically equivalent expression,
provided that the integrity of parentheses is not violated" :
In particular, evaluating an expression using more precision
than the nominal precision of the type of the expression is permitted.
This does not change the type nor the size of the expression but may
affect the value obtained. This latitude has been
historically permitted to Fortran processors since the 1950's.
History:
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Paper 05-283 meeting 174 Submitted